Chemistry:Estradiol-containing birth control pill
| Estradiol-containing oral contraceptive | |
|---|---|
| Background | |
| Type | Hormonal |
| First use | 1993 (Finland ) |
| Pregnancy rates (first year) | |
| Perfect use | ? |
| Typical use | ? |
| Usage | |
| Reversibility | Yes |
| User reminders | ? |
| Advantages and disadvantages | |
| STI protection | No |
Combined birth control pills that contain natural estradiol or an estradiol ester (e.g., estradiol valerate) include:[1][2][3]
- Estradiol valerate and cyproterone acetate (brand name Femilar) – introduced in Finland (only) in 1993[3]
- Estradiol valerate and dienogest (brand names Qlaira, Natazia) – introduced in Europe in 2009 and the U.S. in 2010[4]
- Estradiol and nomegestrol acetate (brand name Zoely) – introduced in Europe in 2011[5]
Estradiol, mainly as esters including estradiol valerate, estradiol cypionate, and estradiol enanthate, is also the exclusive estrogen used in combined injectable contraceptives.[6]
As of 2021, more than 95% of prescriptions are for combined hormonal birth control forms containing the synthetic estrogen ethinylestradiol (EE).[7] Hence, estradiol-based birth control pills are still not widely used.[7]
Side effects
Birth control pills containing estradiol have less impact on liver protein synthesis than ethinylestradiol-containing birth control pills, and it is thought that for this reason, they may pose less of a risk of venous thromboembolism (VTE).[8][9] In accordance, although birth control pills containing estradiol valerate/dienogest are associated with a significantly increased risk of VTE, they are associated with a significantly lower risk of venous thromboembolism than birth control pills containing ethinylestradiol and a progestin.[10] The risk of VTE with estradiol/nomegestrol acetate birth control pills is under study.[11]
Incidence of irregular vaginal bleeding may be higher with estradiol-containing birth control pills in relation to the fact that estradiol is a weaker estrogen than ethinylestradiol in the endometrium.[3]
Pharmacology
The pharmacodynamics and pharmacokinetics of estradiol in the context of use in birth control pills have been studied and reviewed.[12][2][9]
Research
Experimental estradiol-containing birth control pills that were studied but never marketed include:[3]
- Estradiol/norethisterone (Netagen, Netagen 403)
- Estradiol/estriol/norethisterone (Netagen 423)
- Estradiol/estriol/norethisterone acetate
- Estradiol/desogestrel
- Estradiol cyclooctyl acetate/desogestrel
- Estradiol/ethinylestradiol/dienogest
A large randomized controlled trial of a birth control pill containing ethinylestradiol/norethisterone acetate versus a birth control pill containing estradiol/estriol/norethisterone acetate has been conducted.[13]
See also
- Birth control pill formulations
- Estetrol/drospirenone
References
- ↑ "Hormonal contraceptives: pharmacology tailored to women's health". Human Reproduction Update 22 (5): 634–46. 2016. doi:10.1093/humupd/dmw016. PMID 27307386.
- ↑ 2.0 2.1 "Ethinyl estradiol and 17β-estradiol in combined oral contraceptives: pharmacokinetics, pharmacodynamics and risk assessment". Contraception 87 (6): 706–27. 2013. doi:10.1016/j.contraception.2012.12.011. PMID 23375353.
- ↑ 3.0 3.1 3.2 3.3 "Review of clinical experience with estradiol in combined oral contraceptives". Contraception 81 (1): 8–15. 2010. doi:10.1016/j.contraception.2009.08.010. PMID 20004267.
- ↑ "Review of the safety, efficacy and patient acceptability of the combined dienogest/estradiol valerate contraceptive pill". International Journal of Women's Health 2: 279–90. 2010. doi:10.2147/IJWH.S6954. PMID 21151673.
- ↑ "Nomegestrol acetate-17b-estradiol for oral contraception". Patient Preference and Adherence 7: 607–19. 2013. doi:10.2147/PPA.S39371. PMID 23836965.
- ↑ "WJPPS | ABSTRACT". World Journal of Pharmacy and Pharmaceutical Sciences. http://www.wjpps.com/download/article/1412071798.pdf.
- ↑ 7.0 7.1 Mawet, M; Gaspard, Ulysse; Foidart, JM (2021). "Estetrol as estrogen in a combined oral contraceptive, from the first in-human study to the contraceptive efficacy". European Gynecology and Obstetrics 3 (1): 13–21. https://www.egojournal.eu/wp-content/uploads/journal/2021/3.1/13/13-21.pdf. "On the other side, only three different estrogens have been used in COC since 1961: the first one was the pro-drug mestranol rapidly replaced by its potent active form, ethinylestradiol (EE). Ethinylestradiol has remained the only estrogen used in COC during more than four decades. After initial unsuccessful attempts, estradiol (E2) was finally introduced into two COCs in the early 2010’: in the form of the pro-drug E2 valerate in combination with dienogest (E2V/DNG) and in the form of E2 in combination with nomegestrol acetate [4, 5]. However, these E2-containing COCs are less prescribed as over 95% of combined hormonal contraceptive users still utilize an EE-containing product.".
- ↑ "An update on new orally administered contraceptives for women". Expert Opinion on Pharmacotherapy 16 (18): 2759–72. 2015. doi:10.1517/14656566.2015.1100173. PMID 26512437.
- ↑ 9.0 9.1 Jensen, Jeffrey; Bitzer, Johannes; Serrani, Marco (2013). "Comparison of the pharmacologic and clinical profiles of new combined oral contraceptives containing estradiol". Open Access Journal of Contraception: 39. doi:10.2147/OAJC.S50693. ISSN 1179-1527. https://www.researchgate.net/publication/274274938.
- ↑ "Venous thrombosis and hormonal contraception: what's new with estradiol-based hormonal contraceptives?". Open Access J Contracept 9: 75–79. 2018. doi:10.2147/OAJC.S179673. PMID 30519125.
- ↑ "Oral Contraceptives and Venous Thromboembolism: Focus on Testing that May Enable Prediction and Assessment of the Risk". Semin Thromb Hemost 46 (8): 872–886. October 2020. doi:10.1055/s-0040-1714140. PMID 33080636.
- ↑ "Pharmacokinetics of estradiol, free and total estrone, in young women following single intravenous and oral administration of 17β-estradiol". Arzneimittelforschung 43 (9): 966–73. September 1993. ISSN 0004-4172. PMID 8240460.
- ↑ "A randomized, double-blind study of two combined oral contraceptives containing the same progestogen, but different estrogens. World Health Organization Task Force on Oral Contraception". Contraception 21 (5): 445–59. May 1980. doi:10.1016/0010-7824(80)90010-4. PMID 7428356.
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